Author: imp Date: Tue May 15 21:25:35 2018 New Revision: 333648 URL: https://svnweb.freebsd.org/changeset/base/333648
Log: Hold the reference count until the CCB is released When a disk disappears and the periph is invalidated, any I/Os that are pending with the controller can cause a crash when they complete. Move to holding the softc reference count taken in dastart() until the I/O is complete rather than only until xpt_action() returns. (This approach was suggested by Ken Merry.) Sponsored by: Netflix Submitted by: Chuck Silvers Differential Revision: https://reviews.freebsd.org/D15435 Modified: head/sys/cam/scsi/scsi_da.c Modified: head/sys/cam/scsi/scsi_da.c ============================================================================== --- head/sys/cam/scsi/scsi_da.c Tue May 15 21:15:09 2018 (r333647) +++ head/sys/cam/scsi/scsi_da.c Tue May 15 21:25:35 2018 (r333648) @@ -3300,7 +3300,6 @@ out: cam_periph_unlock(periph); xpt_action(start_ccb); cam_periph_lock(periph); - softc->refcount--; /* May have more work to do, so ensure we stay scheduled */ daschedule(periph); @@ -4443,13 +4442,15 @@ dadone(struct cam_periph *periph, union ccb *done_ccb) softc->flags |= DA_FLAG_WAS_OTAG; /* - * We need to call cam_iosched before we call biodone so that we - * don't measure any activity that happens in the completion - * routine, which in the case of sendfile can be quite - * extensive. + * We need to call cam_iosched before we call biodone so that we don't + * measure any activity that happens in the completion routine, which in + * the case of sendfile can be quite extensive. Release the periph + * refcount taken in dastart() for each CCB. */ cam_iosched_bio_complete(softc->cam_iosched, bp, done_ccb); xpt_release_ccb(done_ccb); + KASSERT(softc->refcount >= 1, ("dadone softc %p refcount %d", softc, softc->refcount)); + softc->refcount--; if (state == DA_CCB_DELETE) { TAILQ_HEAD(, bio) queue; _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
